Abstract: A toy building system with function bricks adapted to perform a function in response to a mechanical trigger action; sensor bricks with a sensor adapted to produce an output in response to a mechanical trigger action; and logic bricks with an input responsive to a sensor brick output and adapted to perform a logic function on the sensor brick output and to produce a logic output. The sensor brick output and the logic brick output are arranged in a first uniform manner relative to the coupling means, and the sensor output action and the logic output action are of uniform physical nature. The logic brick input and the function brick input are arranged in a second uniform manner relative to the coupling means. The function brick input is responsive to a logic brick output and adapted to perform the function in response to a logic brick output.